Alliance partners are carriers that participate with a primary airline or alliance in a publicly recognized commercial relationship while being marketed under a single brand or name. By participating in this kind of partnership, airlines expand their flight offerings to cities they do not fly to themselves. Usually the parent airline handles booking and baggage at all points in an itinerary to benefit the passenger. Alliance partner services can include, but are not limited to:

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Frequent traveler mileage accrual

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Reciprocal access to alliance partner airport facilities and other amenities

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Code Share flights

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Redemption

The popular Alliances existent today are as follows:

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Star Alliance

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Skyteam

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Oneworld

Codeshare

An agreement between two airlines in which one airline owns the flight number and markets the flight, and the other airline operates the plane. The first airline is known as the "marketing carrier" and the second airline is known as the operating carrier. These airlines validate tickets on each other’s planes without any restrictions. Code sharing allows the carriers to expand their scope of service and fly to many more destinations without having to increase the size of their fleet. It is a win-win situation for all parties involved.

Interline Practices

This is an agreement between two or more airlines to facilitate the carriage of passengers and cargo, transfer of baggage, and ticketing. For example, a customer could begin a trip with TWA and then connect to a Northwest flight. These interline agreements allow baggage to be automatically transferred from one airline to another. These agreements also allow one ticket to be issued for flights on different airlines. However, not all airlines participate in these agreements so this has to be checked before a ticket is issued for flights on more than one airline.